Preplanned safety analysis of the JFMC37-0801 trial: a randomized phase III study of six months versus twelve months of capecitabine as adjuvant chemotherapy for stage III colon cancer

Background

Six months of adjuvant chemotherapy is regarded as the standard of care for patients with stage III colon cancer. However, whether longer treatment can improve prognosis has not been fully investigated. We conducted a phase III study comparing 6 and 12 months of adjuvant capecitabine chemotherapy for stage III colon cancer, and report here the results of our preplanned safety analysis.

Methods

Patients aged 20–79 years with curatively resected stage III colon cancer were randomly assigned to receive 8 cycles (6 months) or 16 cycles (12 months) of capecitabine (2500 mg/m²/day on days 1–14 of each 21-day cycle). Treatment exposure and adverse events (AEs) were evaluated.

Results

A total of 1304 patients (642 and 636 in the 6-month and 12-month groups, respectively) were analyzed. The most common AE was hand-foot syndrome (HFS). HFS, leukocytopenia, neutropenia, and hyperbilirubinemia (any grade) occurred more frequently in the 12-month group than in the 6-month group. HFS was the only grade ≥3 AE to have a significantly higher incidence in the 12-month group (23 vs 17%, p = 0.011). The completion rate for 8 cycles was 72% in both groups, while that for 16 cycles was 46% in the 12-month group. HFS was the most common AE requiring dose reduction and treatment discontinuation.

Conclusions

Twelve months of adjuvant capecitabine demonstrated a higher cumulative incidence of HFS compared to the standard 6-month treatment period, while toxicities after 12 months of capecitabine were clinically acceptable.

Trial registration

UMIN-CTR, UMIN000001367.

Highly sensitive faecal DNA testing of TWIST1 methylation in combination with faecal immunochemical test for haemoglobin is a promising marker for detection of colorectal neoplasia

Background

As TWIST1 methylation is specific to colorectal neoplasia, detection of TWIST1 methylation from faeces samples might be useful for colorectal neoplasia screening. However, because the content of human DNA in faeces is very small, it is very difficult to detect TWIST1 methylation by conventional bisulphite-based methylation assays. Therefore, we developed a new methylation assay without bisulphite treatment, the combined restriction digital PCR assay, and evaluated its sensitivity and specificity in combination with and without the faecal immunochemical test for haemoglobin for colorectal neoplasia detection from faeces samples.

Methods

For the combined restriction digital PCR assay, DNA was treated with three methylation-sensitive restriction enzymes and an exonuclease, followed by measurement of TWIST1 methylation level by droplet digital PCR. Faecal DNA testing and faecal immunochemical test for haemoglobin were performed on 109 patients with colorectal neoplasia and 10 control individuals.

Results

Basic performance testing showed that the combined restriction digital PCR assay enabled detection of 0.14% of the TWIST1 methylation level for the lymphocyte DNA. The combined restriction digital PCR assay from faeces samples had a sensitivity of 22.2% (95% confidence interval, 2.8–60.0%) for non-advanced adenoma, 47.1% (95% confidence interval, 23.0–72.2%) for advanced adenoma, and 33.7% (95% confidence interval, 23.7–45.0%) for colorectal cancer, and a specificity of 100.0%. Combination of faecal immunochemical test for haemoglobin and faecal combined restriction digital PCR assay increased sensitivity to 82.4% (95% confidence interval, 56.6–96.2%) for the detection of advanced adenoma.

Conclusions

We developed the combined restriction digital PCR assay, a possible highly sensitive methylation assay. Combination of faecal combined restriction digital PCR assay with faecal immunochemical test for haemoglobin may provide an alternative screening strategy for colorectal neoplasia, especially for potentially precancerous lesions.

Phase II clinical trial of peptide cocktail therapy for patients with advanced pancreatic cancer: VENUS-PC study

We previously conducted a phase I clinical trial combining the HLA-A*2402-restricted KIF20A-derived peptide vaccine with gemcitabine for advanced pancreatic cancer (PC) and confirmed its safety and immunogenicity in cancer patients. In this study, we conducted a multicenter, single-armed, phase II trial using two antiangiogenic cancer vaccines targeting VEGFR1 and VEGFR2 in addition to the KIF20A peptide. We attempted to evaluate the clinical benefit of the cancer vaccination in combination with gemcitabine. Chemotherapy naïve PC patients were enrolled to evaluate primarily the 1-year survival rate, and secondarily overall survival (OS), progression free survival (PFS), response rate (RR), disease control rate (DCR) and the peptide-specific immune responses. All enrolled patients received therapy without the HLA-A information, and the HLA genotypes were used for classification of the patients. Between June 2012 and May 2013, a total of 68 patients were enrolled. No severe systemic adverse effects of Grade 3 or higher related to these three peptides were observed. The 1-year survival rates between the HLA-A*2402-matched and -unmatched groups were not significantly different. In the HLA-A*2402 matched group, patients showing peptide-specific CTL induction for KIF20A or VEGFR1 showed a better prognosis compared to those without such induction (P = 0.023, P = 0.009, respectively). In the HLA-A*2402-matched group, the patients who showed a strong injection site reaction had a better survival rate (P = 0.017) compared to those with a weak or no injection site reaction. This phase II study demonstrated that this therapeutic peptide cocktail might be effective in patients who demonstrate peptide-specific immune reactions although predictive biomarkers are needed for patient selection in its further clinical application.

Prediction of the efficacy of immunotherapy by measuring the integrity of cell-free DNA in plasma in colorectal cancer

We previously reported a phase II study of a cancer vaccine using five novel peptides recognized by HLA‐A*2402‐restricted CTL in combination with oxaliplatin‐containing chemotherapy (FXV study) as first‐line therapy for patients with metastatic colorectal cancer and demonstrated the safety and promising potential of our five‐peptide cocktail. The objective of this analysis was to identify predictive biomarkers for identifying patients who are likely to receive a clinical benefit from immunochemotherapy. Circulating cell‐free DNA (cfDNA) in plasma has been reported to be a candidate molecular biomarker for the efficacy of anticancer therapy. Unlike uniformly truncated small‐sized DNA released from apoptotic normal cells, DNA released from necrotic cancer cells varies in size. The integrity of plasma cfDNA (i.e. the ratio of longer fragments [400 bp] to shorter fragments [100 bp] of cfDNA), may be clinically useful for detecting colorectal cancer progression. We assessed plasma samples collected from 93 patients prior to receiving immunochemotherapy. The cfDNA levels and integrity were analyzed by semi‐quantitative real‐time PCR. Progression‐free survival was significantly better in patients with a low plasma cfDNA integrity value than in those with a high value (P = 0.0027). Surprisingly, in the HLA‐A*2402‐matched group, patients with a low plasma cfDNA integrity value had significantly better progression‐free survival than those with a high value (P = 0.0015). This difference was not observed in the HLA‐A*2402‐unmatched group. In conclusion, the integrity of plasma cfDNA may provide important clinical information and may be a useful predictive biomarker of the outcome of immunotherapy in metastatic colorectal cancer.

MicroRNA-6826 and -6875 in plasma are valuable non‑invasive biomarkers that predict the efficacy of vaccine treatment against metastatic colorectal cancer

Various vaccine treatments against metastatic colorectal cancer have been developed and applied. However, to improve the efficacy of immunotherapy, biomarkers that can predict the effects are needed. It has been reported that various microRNAs (miRNAs) in peripheral blood may be useful as non-invasive biomarkers. In this study, miRNAs influencing the efficacy of vaccine treatment were screened for in a microarray analysis of 13 plasma samples that were obtained from patients prior to vaccine treatment. To validate the screening results, real-time RT-PCR was performed using 93 plasma samples obtained from patients prior to vaccine treatment. Four candidate miRNAs were selected according to the results of the comprehensive analysis of miRNA expression, which were ranked using the Fisher criterion and the absolute value of the log2 ratio in the screening analysis. The validation analysis showed that in the HLA-A*2402-matched patient group (vaccine-treated group), patients with a high expression of plasma miR-6826 had a poorer prognosis than those with a low expression (P=0.048). In contrast, in the HLA-A*2402-unmatched patient group (control group), there was no difference between the patients with high or low plasma miR-6826 expression (P=0.168). Similar results were obtained in the analysis of miR-6875 (P=0.029 and P=0.754, respectively). Moreover, multivariate analysis of the Cox regression model indicated that the expression of miR-6826 was the most significant predictor for overall survival (P=0.003, hazard ratio, 3.670). In conclusion, plasma miR-6826 and miR-6875 may be predictive biomarkers for a poor response to vaccine treatment. Although further clarification is needed regarding the functions of miR-6826 and miR-6875 and their relationship to immune-related molecules, plasma miR-6826 and miR-6875 may be useful negative biomarkers for predicting the efficacy of vaccine treatment.

Association of tumor necrosis factor-α polymorphism with chemotherapy-induced oral mucositis in patients with esophageal cancer

The purpose of this study was to evaluate the association between tumor necrosis factor (TNF)-α polymorphisms and oral mucositis (OM) from 5-fluorouracil (5-FU) plus cisplatin (CDDP) chemotherapy for esophageal cancer. The rs1799964 polymorphism of TNF-α was genotyped using the tetra-primer amplification refractory mutation system polymerase chain reaction. The experimental group comprised 64 patients who received chemotherapy for esophageal cancer between 1997 and 2004; a total of 106 patients between 2005 and 2013 were investigated as the validation group. Univariate analysis of the experimental group revealed that the TT genotype of TNF-α rs1799964 was significantly higher in patients with grade 1-4 OM compared with the TC/CC genotypes [univariate odds ratio (OR)=4.0; P=0.029]. Similarly, univariate analysis of the validation group revealed that the percentage of the TT genotype was significantly higher in patients with grade 1-4 OM compared with the TC/CC genotypes (OR=2.8; P=0.043). This difference in risk was replicated in the validation cohort. Thus, the TT genotype of TNF-α rs1799964 may be a predictor of chemotherapy-induced OM in patients with esophageal cancer.

Calreticulin is highly expressed in pancreatic cancer stem-like cells

Cancer stem‐like cells (CSLCs) in solid tumors are thought to be resistant to conventional chemotherapy or molecular targeting therapy and to contribute to cancer recurrence and metastasis. In this study, we aimed to identify a biomarker of pancreatic CSLCs (P‐CSLCs). A P‐CSLC‐enriched population was generated from pancreatic cancer cell lines using our previously reported method and its protein expression profile was compared with that of parental cells by 2‐D electrophoresis and tandem mass spectrometry. The results indicated that a chaperone protein calreticulin (CRT) was significantly upregulated in P‐CSLCs compared to parental cells. Flow cytometry analysis indicated that CRT was mostly localized to the surface of P‐CSLCs and did not correlate with the levels of CD44v9, another P‐CSLC biomarker. Furthermore, the side population in the CRT^high/CD44v9^low population was much higher than that in the CRT^low/CD44v9^high population. Calreticulin expression was also assessed by immunohistochemistry in pancreatic cancer tissues (n = 80) obtained after radical resection and was found to be associated with patients' clinicopathological features and disease outcomes in the Cox proportional hazard regression model. Multivariate analysis identified CRT as an independent prognostic factor for pancreatic cancer patients, along with age and postoperative therapy. Our results suggest that CRT can serve as a biomarker of P‐CSLCs and a prognostic factor associated with poorer survival of pancreatic cancer patients. This novel biomarker can be considered as a therapeutic target for cancer immunotherapy.

[A Case of Borderline Resectable Pancreatic Cancer Responding to Preoperative GEM plus Nab-PTX Combination Chemotherapy]

We report a case of borderline resectable(BR)pancreatic cancer, which was eligible for R0 resection following preoperative chemotherapy with GEM plus nab-PTX. A 77-year-old woman presented with brown urine and clay-colored stool. After further examination, she was diagnosed with obstructive jaundice due to pancreatic head cancer. Because the tumor was in contact with the region attached to the SMA nerve plexus, she was also diagnosed with BR-A pancreatic cancer. After 6 courses of preoperative GEM plus nab-PTX combination chemotherapy, she underwent subtotal stomach-preservingpancreaticoduodenectomy with SMV resection and right semicircular SMA nerve plexus dissection. In the histopathological diagnosis, malignant cells were observed at low levels in both the pancreatic parenchyma and duodenal mucosa. There were no findings of residual malignant cells in the wall of the SMV or in the nerve plexus around the SMA. Since the final diagnosis was pT3,(DU+), pN0, cM0, fStage III , we concluded that the R0 resection as complete. Histological therapeutic evaluation with the Evans classification concluded that the disease was Grade III . GEM plus nab-PTX combination chemotherapy could be considered for preoperative chemotherapy, which may allow R0 resection for BR pancreatic cancer.

[Unresectable Stage IV Sigmoid Colon Cancer with Extended Resection for Primary Tumor - A Case Report]

A 65-year-old woman who was diagnosed with unresectable Stage IV sigmoid colon cancer underwent transverse colostomy with double orifices. Although KRAS gene mutation was observed, we could not administer bevacizumab because of the risk of bleeding from the primary tumor and peritumoral abscess. We started bi-weekly XELOX therapy but bloody bowel discharge continued. We planned extended resection of the primary tumor in order to control the bleeding and perforation. Sigmoidectomy, partial resection of the left ureter and small intestine, partial hysterectomy, bilateral salpingo-oophorectomy, and umbilical tumor resection were performed and the patient was discharged on the 10th day after surgery. After surgery, bloody bowel discharge disappeared and bevacizumab was administered in the 55th day. Extended resection for a primary tumor may contribute to bleeding control and broaden treatment options.

[Two Cases of Primary Hepatic Mucosa-Associated Lymphoid Tissue(MALT) Lymphoma]

Case 1: A 57-year-old woman with chronic hepatitis related to the hepatitis B virus was found to have a liver tumor on ultrasonography(US). Computed tomography(CT), magnetic resonance imaging(MRI), and angiography revealed 2 tumors in the liver. The patient underwent right anterior sectorectomy, and histopathologic analysis revealed mucosa-associated lymphoid tissue(MALT)lymphoma. Thirty months later, recurrence was confirmed using liver biopsy. CR was confirmed after radiation and chemotherapy, and the patient has survived. Case 2: A 71-year-old woman came to our hospital for rheumatism treatment. US, CT, and MRI revealed a tumor in the left lateral segment of the liver. The patient underwent laparoscopic partial liver resection and histopathologic analysis revealed MALT lymphoma. The patient has survived.

[A Case of Esophageal Submucosal Tumor Undiagnosed Preoperatively and Treated with Thoracoscopic Enucleation]

An asymptomatic 35-year-old man visited our hospital because of an esophageal abnormality identified on a medical check-up. Gastrointestinal endoscopic examination revealed a 4 cm diameter submucosal tumor(SMT)in the upper esophagus. endoscopic ultrasound fine-needle aspiration biopsy(EUS-FNAB)was performed. Histopathological examination showed that it was strongly positive for a-SMA and partially positive for c-kit. An esophageal leiomyoma was suspected but esophageal gastrointestinal stromal tumor(GIST)could not be completely ruled out. After considering the patient's age and the location of the tumor, we performed thoracic enucleation of the esophageal SMT. Immunostaining findings showed that it was a-SMA positive and S-100 negative. Mast cells, but not tumor cells were partially stained with c-kit. The final pathological diagnosis was leiomyoma. The postoperative course was uneventful. We report this case together with a review of the literature.

[Long-Term Survival of a Patient with Recurrent Duodenal GIST Treated with Various Molecular Targeted Drugs and TAE - A Case Report]

The patient was 66-year-old woman with anemia. A 6 cm GIST was diagnosed in the fourth portion of the duodenum using abdominal CT. Duodenal-jejunal segmental resection was performed for the GIST. Four years after surgery, multiple liver metastatic recurrences ofGIST were diagnosed using abdominal CT. The metastatic tumor was treated with imatinib, but the treatment caused adverse events such as leukocytopenia(Grade 2)and anemia(Grade 3). The treatment continued for 41 months while reduced or discontinued during the administration period. Sunitinib was administered, but the treatment caused a reduced platelet count(Grade 3), anemia(Grade 2), and melena(Grade 3). The treatment continued for 12 months while reduced or discontinued during the administration period. Regorafenib was administered and continued for 9 months. Thereafter, trancecatheter arterial embolization(TAE)was performed 5 times. The patient is alive 8 years and 3 months after recurrence.

[Use of a Posterior Thigh Flap with the Gluteus Maximus for Perineal Reconstruction - A Case of Fournier's Gangrene with Rectal Cancer]

We present a case of Fournier's gangrene secondary to rectal cancer that was managed with perineal reconstruction using a posterior thigh flap after debridement and tumor resection. A 67-year-old man was admitted with disturbed consciousness as well as hip and right thigh pain. His perineal and gluteal skin was necrotic. CT revealed subcutaneous emphysema that had spread from the rectum to the gluteal region and right thigh. We diagnosed him with Fournier's gangrene, and then removed the necrotic tissue and constructed a sigmoidostomy. A diagnosis of rectal cancer was later confirmed. Fifty-nine days after the initial operation, a laparoscopic abdominoperineal resection was performed. The perineal defect was repaired using a posterior thigh flap with the gluteus maximus. There were no postoperative complications, and the patient was discharged ahead of schedule. We concluded that the use of a posterior thigh flap is a good choice for perineal reconstruction, because it is simple to perform, can cover a large area, and has a low risk of infection.

[A Case of Ascending Colon Cancer with Extensive Abdominal Wall Abscess]

A 51-year-old woman was seen in our hospital because an ascending colon tumor with extensive abdominal wall abscess was detected on computed tomography(CT). On the same day, we performed open drainage and laparoscopic assisted ileocolostomy. Postoperative day 35, we performed right hemicolectomy with abdominal wall resection and closure of the colostomy as a radical surgery. After surgery, we started(negative pressure wound therapy: NPWT)to the surgical wound site; hence, the abdominal wall defect could be healed without a musculocutaneous flap. Laparoscopic assisted open drainage, a two-stage operation, and NPWT are useful in a case of colon cancer with abdominal wall abscess.

Highly sensitive stool DNA testing of Fusobacterium nucleatum as a marker for detection of colorectal tumours in a Japanese population

Background Accumulating evidence shows an over-abundance of Fusobacterium nucleatum in colorectal tumour tissues. Although stool DNA testing of Fusobacterium nucleatum might be a potential marker for the detection of colorectal tumours, the difficulty in detecting Fusobacterium nucleatum in stool by conventional methods prevented further explorations. Therefore, we developed a droplet digital polymerase chain reaction (PCR) assay for detecting Fusobacterium nucleatum in stool and investigated its clinical utility in the management of colorectal tumours in a Japanese population. Methods Feces were collected from 60 healthy subjects (control group) and from 11 patients with colorectal non-advanced adenomas (non-advanced adenoma group), 19 patients with colorectal advanced adenoma/carcinoma in situ (advanced adenoma/carcinoma in situ (CIS) group) and 158 patients with colorectal cancer of stages I to IV (colorectal cancer group). Absolute copy numbers of Fusobacterium nucleatum were measured by droplet digital PCR. Results The median copy number of Fusobacterium nucleatum was 17.5 in the control group, 311 in the non-advanced adenoma group, 122 in the advanced adenoma/CIS group, and 317 in the colorectal cancer group. In comparison with that in the control group, the Fusobacterium nucleatum level was significantly higher in the non-advanced adenoma group, the advanced adenoma/CIS group and the colorectal cancer group. Conclusions This study illustrates the potential of stool DNA testing of Fusobacterium nucleatum by droplet digital PCR to detect individuals with colorectal tumours in a Japanese population.

Combined adjuvants of poly(I:C) plus LAG-3-Ig improve antitumor effects of tumor-specific T cells, preventing their exhaustion

Therapeutic cancer vaccines are designed to treat cancer by boosting the endogenous immune system to fight against the cancer. In the development of clinically effective cancer vaccines, one of the most practical objectives is to identify adjuvants that are capable of optimizing the vaccine effects. In this study, we explored the potential of polyinosinic-polycytidylic acid (poly(I:C)) and LAG-3-Ig (soluble recombinant protein of lymphocyte activation gene-3 [LAG-3] extracellular domain fused with human IgG Fc region) as adjuvants for P1A tumor antigen peptide vaccine in a pre-established P815 mouse tumor model with a transfer of tumor-specific T cells. Whereas the use of poly(I:C) or LAG-3-Ig as a signal adjuvant induced a slight enhancement of P1A vaccine effects compared to incomplete Freund's adjuvant, combined treatment with poly(I:C) plus LAG-3-Ig remarkably potentiated antitumor effects, leading to complete rejection of pre-established tumor and long-term survival of mice. The potent adjuvant effects of poly(I:C) plus LAG-3-Ig were associated with an enhanced infiltration of T cells in the tumor tissues, and an increased proliferation and Th1-type cytokine production of tumor-reactive T cells. Importantly, the combined adjuvant of poly(I:C) plus LAG-3-Ig downregulated expressions of PD-1, LAG-3, and TIGIT on P1A-specific T cells, indicating prevention of T cell exhaustion. Taken together, the results of the current study show that the combined adjuvants of poly(I:C) plus LAG-3-Ig with tumor peptide vaccine induce profound antitumor effects by activating tumor-specific T cells.

A Phase II Study of XELOX and Cetuximab as First-Line Therapy in Patients With KRAS Wild Type Metastatic Colorectal Cancer (FLEET2 Study)

BACKGROUND

Despite the comparable clinical benefit of XELOX (capecitabine with oxaliplatin) and FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), the value of XELOX treatment in combination with cetuximab for metastatic colorectal cancer (mCRC) remains largely unknown.

PATIENTS AND METHODS

In this clinical trial we evaluated the efficacy and safety of weekly/biweekly cetuximab administration combined with biweekly XELOX in patients with previously untreated v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) wild type mCRC. The primary end point was response rate (RR) with confirmation, and the secondary end points included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), dose intensity, and the safety of the protocol treatment.

RESULTS

Forty patients who fulfilled the inclusion criteria participated in this study. The median treatment cycle number was 8 and the median dose intensities were 218 mg/m²/wk for cetuximab, 34 mg/m²/wk for oxaliplatin, and 821 mg/m²/d for capecitabine. One patient showed complete response and partial response was observed in 19 patients, giving an overall RR of 50% (95% confidence interval [CI], 33.8%-66.2%). Stable disease was obtained in 13 patients, resulting in a DCR of 82.5% (95% CI, 67.2%-92.7%). The PFS was 6.5 months (95% CI, 3.5-9.6 months), and the OS was 24.3 months (95% CI, 14.9-33.7 months). The safety profile revealed the common Grade 3/4 adverse events to be acneiform eruption (12.5%), peripheral neuropathy (7.5%), and elevated alanine transaminase levels (7.5%). Grade 3/4 thrombocytopenia and neutropenia occurred only in 5.0% and 2.5% of the patients, respectively. Grade 1 hand-foot syndrome (HFS) was not uncommon (20%), whereas Grade 2/3 HFS occurred in only 3 patients (7.5%). No deaths were reported within 30 days of the last dose.

CONCLUSION

Cetuximab with XELOX showed a confirmed overall RR of 50%, which was within the previously reported range of RR. The safety profile showed an acceptable rate and severity of adverse events. In light of the several advantages of XELOX, including convenience and the reported cost-saving aspects, further study of this combination therapy is warranted.

Protocol of a randomised phase III clinical trial of sequential capecitabine or 5-fluorouracil plus bevacizumab (Cape/5-FU-Bmab) to capecitabine or 5-fluorouracil plus oxaliplatin plus bevacizumab (CapeOX/mFOLFOX6-Bmab) versus combination CapeOX/mFOLFOX6-Bmab in advanced colorectal cancer: the C-cubed (C3) study

INTRODUCTION

Results from several randomised trials suggest that the sequential use of cytotoxic agents in patients with metastatic colorectal cancer (mCRC) has the potential to improve overall survival compared with combination chemotherapy. This study is designed to investigate whether sequential treatment with bevacizumab-based first-line treatment with oxaliplatin is superior to combination treatment of mCRC.

METHODS AND ANALYSIS

The C-cubed (C(3)) study is a two-arm, multicentre, open-label, randomised phase III trial in Japan comparing the efficacy and safety of sequential capecitabine or 5-fluorouracil plus bevacizumab (Cape/5-FU-Bmab) with escalation to capecitabine or 5-fluorouracil plus oxaliplatin plus bevacizumab (CapeOX/mFOLFOX6-Bmab) versus combination CapeOX/mFOLFOX6-Bmab as the first-line treatment of mCRC. In the sequential arm (Arm A: oxaliplatin 'wait-and-go'), treatment escalation from Cape/5-FU-Bmab to CapeOX/mFOLFOX6-Bmab is recommended in the case of progressive disease. In the combination arm (Arm B: oxaliplatin 'stop-and-go'), de-escalation from CapeOX/mFOLFOX6-Bmab to Cape/5-FU-Bmab is possible after 12 weeks of treatment. Re-escalation to CapeOX/mFOLFOX6-Bmab after progressive disease is considered only for patients who received de-escalation of oxaliplatin after 12 weeks of treatment not caused by oxaliplatin-associated toxicity. A target sample size of 304 evaluable patients is considered sufficient to validate an expected HR for time to failure of strategy of the sequential approach 'wait-and-go' compared to the combination approach 'stop-and go' with 80% power and 2-sided 5% α in case of a true HR<0.69.

ETHICS AND DISSEMINATION

This study is conducted according to the standards of Good Clinical Practice and in compliance with the Declaration of Helsinki 2013 and local regulations, and has been submitted and approved by the Ethical Committee of the Non-Profit Organization MINS Institutional Review Board. The protocol and the trial results, even inconclusive, will be presented at international oncology congresses and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

UMIN000015405, Pre-results.

Characterization of the T cell repertoire by deep T cell receptor sequencing in tissues and blood from patients with advanced colorectal cancer

The aim of the present study was to characterize infiltrated T cell clones that define the tumor immune environment and are important in the response to treatment in patients with advanced colorectal cancer (CRC). In order to explore predictive biomarkers for the efficacy of immunochemotherapies, T cell receptor (TCR) repertoire analysis was performed using blood samples and tumor tissues obtained from patients with advanced CRC that had been treated with a combination of five-cancer peptide vaccines and oxaliplatin-based chemotherapy. The TCR-α/β complementary DNAs (cDNAs), prepared from the messenger RNAs (mRNAs) obtained from 17 tumor tissues and 39 peripheral blood mononuclear cells of 9 CRC patients at various time points, were sequenced. The oligoclonal enrichment of certain TCR sequences was identified in tumor tissues and blood samples; however, only a few TCR sequences with a frequency of >0.1% were commonly detected in pre- and post-treatment tumor tissues, or in post-treatment blood and tissue samples. The average correlation coefficients of the TCR-α and TCR-β clonotype frequencies between the post-treatment tumor tissues and blood samples were 0.023 and 0.035, respectively, and were much lower compared with the correlation coefficients of the TCR-α and TCR-β clonotype frequencies between pre- and post-treatment blood samples (0.430 and 0.370, respectively), suggesting that T cell populations in tumor tissues vary from those in blood. Although the sample size was small, a tendency for the TCR diversity in tumor tissues to drastically decrease during the treatment was indicated in two patients, who exhibited a longer progression-free survival time. The results of the present study suggest that TCR diversity scores in tissues may be a useful predictive biomarker for the therapeutic effect of immunochemotherapy for patients with advanced CRC.

Efficacy and Safety of Biweekly Docetaxel in Combination with Nedaplatin as Second-line Chemotherapy for Unresectable or Recurrent Esophageal Cancer

AIM

In Japan, chemotherapeutic agents that have been approved for the treatment of esophageal cancer include cisplatin, nedaplatin, 5-fluorouracil, vindesine, and docetaxel. The aim of this study was to retrospectively investigate the efficacy and safety of docetaxel and nedaplatin combination chemotherapy for unresectable or recurrent esophageal cancer in an outpatient setting.

PATIENTS AND METHODS

In total, 33 patients with recurrent esophageal cancer after initial treatment (esophagectomy, chemotherapy, or chemoradiotherapy) were enrolled. Patients received docetaxel (30 mg/m(2)intravenously) and nedaplatin (30 mg/m(2)intravenously) on day 1 biweekly. The response rate (RR), time to treatment failure (TTF), overall survival time (OS), and toxicity were analyzed.

RESULTS

The median number of cycles of combination therapy was five (range=2-25 cycles). The RR was 21.2%, and the disease control rate was 60.6%. The median TTF was 71 days, and median OS was 211 days. The most frequent toxicities were leukopenia and anemia; non-hematological toxicities were generally mild. There were no treatment-related deaths.

CONCLUSION

This outpatient combination chemotherapy was useful as second-line chemotherapy for unresectable or recurrent esophageal cancer.

[A Case of a Submucosal Tumor-Like Gastric Cancer That Needed to Be Distinguished from Gastric Metastasis of Rectal Cancer]

A 56-year-old man who underwent a radical operation and adjuvant chemotherapy for recurrent rectal cancer had been followed-up and had no recurrence for one and a half years. Thereafter, CT and upper endoscopy showed a submucosal tumor with a central recess developing in the stomach wall. It was suspected that the gastric tumor was either a metastasis of rectal cancer or a submucosal tumor-like gastric cancer. We performed a radical operation to remove the lesion. In the resected specimen, immunohistopathological findings including HER2 status suggested that the gastric tumor was a primary gastric cancer resembling a submucosal tumor.